Universal grinding machines, which are used for different grinding processes, require tools of different shapes in order to perform the desired grinding operations. All these grinding machines have a expanding mandrel of similar construction which fits into the chuck of the grinding spindle, and the tools are disposed in a tool magazine from which they can be withdrawn in order to change a tool and in which they can be inserted again.
Changing the tool, which is usually carried out manually, is laborious and time-consuming. There is also the problem of supplying coolant to the tool at the correct location for cooling the tool during grinding, since the point of action between the tool and the workpiece and the point of highest stress on the tool are different for grinding tools of different shapes. After changing a tool, the coolant supply therefore has to be re-aligned each time also, and if necessary the coolant nozzle also has to be changed, in order to effect the optimum cooling of the tool. This consumes a considerable amount of time, during which the machine cannot operate.